This disclosure relates to a fuel float valve. More particularly, the disclosure relates to a fuel float valve for use in an aircraft fuel system.
One typical fuel system for an aircraft includes multiple fuel tanks. A surge tank is fluidly connected to at least one of the fuel tanks. A nitrogen generation system provides nitrogen to the fuel tanks to fill any gaseous cavities with inert gas.
A fuel float valve is arranged in one of the fuel tanks to selectively vent gases from the fuel tank to the surge tank. One type of fuel float valve is a flapper valve in which a float is arranged on one side of a beam and a plate is arranged on the other side of the beam. The beam pivots about a fulcrum. As the fuel level rises within the tank, the flapper valve pivots to seal an opening in a wall in the fuel tank with the plate. The plate blocks fluid flow from the fuel tank to the surge tank, for example, during turning maneuvers.
Under some conditions, the plate may undesirably remain sealed against the wall after the fuel level falls. For example, the nitrogen generation system may generate enough pressure in some circumstances to maintain the plate in the closed position. However, the fuel tank should again be permitted to vent to the surge tank.